Ultrastructural Analysis of a Form of Macular Degeneration - Macular Telangiectasia

一种黄斑变性 - 黄斑毛细血管扩张症的超微结构分析

• 批准号: 9978226
• 负责人: JOHN E DOWLING
• 金额: $ 25.35万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9978226
• 关键词: 3-Dimensional; Affect; Age; Age related macular degeneration; Age-Years; American; Anabolism; Area; Biological; Blood-Retinal Barrier; Cells; Characteristics; Computer software; Crista ampullaris; Data; Daughter; Defect; Dependence; Development; Disease; Electrons; Enzymes; Etiology; Eye; Face; Fiber; Future; Genes; Geographic Locations; Goals; Health; Human; Image; Image Analysis; Intelligence; Learning; Link; Macular degeneration; Maintenance; Membrane; Metabolic; Metabolic Pathway; Metabolism; Methodology; Methods; Microscopic; Microtome - medical device; Mitochondria; Morphology; Mothers; Muller' s cell; Neurodegenerative Disorders; Neuroglia; Neurons; Organelles; Pathologic; Pathway interactions; Peripheral; Phosphoglycerate dehydrogenase; Photoreceptors; Pigments; Play; Presynaptic Terminals; Process; Resolution; Retina; Retinal Degeneration; Sampling; Serine; Site; Speed; Sphingolipids; Structure; Synapses; Techniques; Telangiectasis; Thick; Time; Tissues; Ursidae Family; Vision; Visual Acuity; Woman; Work; base; data acquisition; design; disorder control; early onset; experience; fovea centralis; genome wide association study; improved; insight; interest; ionic balance; lipid metabolism; macula; metabolomics; neurotransmission; retinal neuron; tissue processing

Project Summary/Abstract: Little is known about the cellular interactions within the human macula/fovea. This is especially true for interactions between retinal glial cells and retinal neurons – interactions likely important to understanding retinal degenerative diseases including Macular Telangiectasia (MacTel), a form of age-related macular degeneration (AMD) in which it has been proposed that a defect in the Müller glial cells may be at play. Müller glia cells are relied upon to regulate ionic balance and neurotransmission, maintain metabolic stasis, constitute the blood-retinal barrier, among multiple other essential neuroprotective functions. An increasing focus has been on the dependence of retinal neurons on Müller cell based L-serine biosynthesis since retinal neurons (as do neurons throughout the CNS) lack the rate limiting biosynthetic enzyme PHGDH. L-serine synthesis is essential for lipid metabolism and maintenance of mitochondrial function. Not only have metabolomics studies implicated alterations in the L-serine metabolic pathway in the development of MacTel but genome-wide association/GWAS studies have linked alterations in the PHGDH gene with early onset MacTel. Not surprisingly, alterations in the normal relationships between neurons and glial cells feature prominently in maintaining normal retinal function and are implicated in the etiology of multiple forms of retinal degeneration. In recent years, electron microscopic (EM) techniques have been developed such that it is now possible to reconstruct pieces of retinal tissue down to the membrane level. Termed connectomics, it is possible to cut and collect on tape, thousands of serial sections, and image specific regions of the sections with an EM that has multiple beams, allowing for 61 images to be obtained simultaneously. Software methods for aligning the images into a single 3D volume have also been developed. To date, this connectomics approach has not been applied to gaining an understanding of pathological changes that underlie retinal degenerative diseases. The first aim in our current proposal is to determine the structural features/changes in glial-neuronal relationships and mitochondrial health involved in MacTel. These studies will focus especially on the cristae structure of mitochondria, mitochondrial degradation, and the relationship between Müller cells and the photoreceptor axons and synaptic terminals. We have made significant progress in making the typically lengthy connectomics workflow more efficient and tailored to analyzing the basis of a neurodegenerative disease. Using our targeted high-throughput connectomics approach our second aim is to perform parallel analysis of our genetically similar 79-year-old donor eye and other retinas using methods refined from our experience working with our 48-year-old donor eye. In summary, we are confident that our targeted high-throughput connectomics approach will enable us to efficiently extract relevant ultrastructural data from multiple diseased and control retinal samples. In future, having the ability to perform efficient large-scale ultrastructural studies will provide a pathway to understand the cellular basis of retinal degenerative diseases.

项目摘要/摘要： 对于人类黄斑/中央凹内的细胞相互作用知之甚少，对于人类黄斑/中央凹内的细胞相互作用尤其如此。 视网膜神经胶质细胞和视网膜神经元之间的相互作用——相互作用可能对理解很重要 视网膜退行性疾病，包括黄斑毛细血管扩张症 (MacTel)，这是一种与年龄相关的黄斑病变 变性（AMD），有人提出穆勒神经胶质细胞的缺陷可能在其中发挥作用。 神经胶质细胞依赖于调节离子平衡和神经传递，维持代谢停滞，构成 血视网膜屏障以及其他多种重要的神经保护功能受到越来越多的关注。 自从视网膜神经元（如 整个神经元（CNS）缺乏L-丝氨酸合成的限速生物合成酶。 对于脂质代谢和维持线粒体功能至关重要 不仅有代谢组学研究。 MacTel 发育过程中涉及 L-丝氨酸代谢途径的改变，但在全基因组范围内 协会/GWAS 研究已将 PHGDH 基因的改变与早发 MacTel 联系起来。 令人惊讶的是，神经元和神经胶质细胞之间正常关系的改变在 维持正常的视网膜功能，并与多种形式的视网膜变性的病因有关。 近年来，电子显微镜（EM）技术得到了发展，现在 可以将视网膜组织碎片重建到膜水平，这是终止的连接组学。 可以在磁带上切割和收集数千个连续切片，并对切片的特定区域进行成像 使用具有多个光束的 EM，可以同时获取 61 个图像。 迄今为止，还开发了用于将图像对齐到单个 3D 体积的连接组学。 方法尚未应用于了解其背后的病理变化 我们当前提案的首要目标是确定视网膜退行性疾病的结构。 MacTel 涉及的神经胶质-神经元关系和线粒体健康的特征/变化。 将特别关注线粒体嵴结构、线粒体降解及其关系 我们在穆勒细胞与感光轴突和突触末梢之间的研究方面取得了重大进展。 使通常冗长的连接组学工作流程更加高效，并针对分析基础进行定制 使用我们的靶向高通量连接组学方法，我们的第二个目标是 使用方法对我们基因相似的 79 岁捐赠者眼睛和其他视网膜进行并行分析 根据我们与 48 岁捐献者眼睛合作的经验总结，我们对我们的工作充满信心。 有针对性的高通量连接组学方法将使我们能够有效地提取相关的超微结构数据 未来，有能力从多个患病和对照视网膜样本中进行高效的大规模研究。 超微结构研究将为了解视网膜退行性疾病的细胞基础提供一条途径。